1. Field of the Invention
The present invention relates to a flexible printed wiring board. More particularly, the present invention relates to a flexible printed wiring board which can be connected to a connector in a reliably set manner of terminals without deviations or errors.
2. Description Related to the Prior Art
It has been recently suggested to reduce sizes and thicknesses of electronic instruments. Density of circuits used for them are increased by use of integrated circuits (IC), large-scale integration (LSI), parts of chips and the like. Printed circuit boards are used with flexible printed wiring board which connects them with one another. It has been also suggested to increase density of patterned lines included in the flexible printed wiring board.
The flexible printed wiring board includes a terminal section in which ends of the patterned lines are uncovered externally. A connector has an insertion slot, in which the terminal section is inserted and retained by a retaining mechanism of the connector fixedly, so as to connect the patterned lines with respectively contact points of the connector. If the patterned lines are disposed in a high density in the flexible printed wiring board, there arises a problem in that an uncovered area of the patterned lines is small at the terminal section. Thus failure in the contact is likely to occur. It is known that terminals of the terminal section are provided with a great width typically in the flexible printed wiring board with great density, because portions of the patterned lines at the terminal section are disposed in a zigzag manner.
However, the arrangement of the terminals of the terminal section at a small pitch in a zigzag is likely to result in failure in the connection, particularly when the terminal section is inserted only a small amount, or with an inclination to the insertion direction.
JP-A 07-170040 discloses a construction with signs provided in the patterned lines in the flexible printed wiring board for the purpose of acceptable insertion of the terminal section into the connector. The use of signs in the patterned lines are certainly effective in checking an amount of the insertion of the terminal section. However a problem lies in that it is difficult to check straightness of the terminal section relative to the connector.
JP-A 09-129323 discloses a construction with positioning projections and positioning holes in each of the connector and the flexible printed wiring board for the purpose of acceptable insertion of the terminal section into the connector. However there is a problem in that the connector and the flexible printed wiring board must have a great size due to the projections and holes. At the time of connection or disconnection of the flexible printed wiring board, portions having the projections and holes must be eliminated. So efficiency in the connecting or disconnecting operation is low.